The expert wrote: “I am dead! Look at the detail on the back of Catherine’s Philip Treacy hat.
“It is finished with a button matching her Andrew GN Coat. It just screams ‘Queen’!”
Royal fans loved this little detail, with @bergi1954 tweeting: “HRH The Princess of Wales!! The attention to detail is impeccable!”
Another fan, @AndisMom4 wrote: “She is magnificent! Such attention to detail.”
Royal watcher @Muskadoptme said: “I know! I thought the front of the hat was amazing but the back is just as incredible.
“She looks absolutely gorgeous in that green.” Similarly, @Mystifeye commented: “She looks gorgeous, as usual. The woman is stunning, truly.”
Twitter user @RoyalistTilly added: “Well spotted. Missed that detail as I had zoomed in to see the detail on the chair at the back.”
Another fan, @EvalinaPrincess commented: “I like it better from this view. Such regal bearing—presents every outfit to its advantage.”
Royal watcher @emerald88604982 said: “Matching detail on the front of the dress! Magnificent.”
Another fan, @liza_falls added: “A wonderful touch adding a button matching her dress to the bow of her hat!
“The whole outfit is simply gorgeous. I hope we see more of Andrew Gn.”
Twitter user @pelaez4_pelaez said: “She is always so good with the details. Maybe it was her dresser or the designer who suggested it, but she always goes with an immaculately put-together outfit.”